Specifications
The following are the technical parameters and specifications of the Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA).
Standard reference paper
There is a reference paper describing KAIRA. It serves as an introduction to the KAIRA facility, its technical capability and provides an open-access, standard reference paper for anyone referring to the KAIRA instrument or data in their own thesis or publication.General
| Location | Kilpisjärvi |
| Country | Finland |
| Operated by | Sodankylä Geophysical Observatory |
| Receiver Units (RCUs) | 96 |
| Remote Station Processor (RSP) boards | 12 |
| RCU modes used | 0,3,4,5,6,7 |
| RCU modes available, but not used | 1,2 |
| Sample clock frequency | 160 or 200 MHz |
| Raw sample type | 12-bit |
| Subbands (frequnecy channels) | 512 |
| Beamlets | 244 (12-bit mode) or 488 (8-bit mode) or 976 (4-bit mode, limited) |
Array parameters
The following are the parameters on an array basis. Note that it is possible to mix parts of the array for combined experiments.| Array parameters | LBA | HBA |
| Number of antennas | 48 | 48 |
| Antenna type | Inverted-V dipoles | 16-element tiles |
| Polarisation per antenna | 2 | 2 |
| Array layout | sparse, quasi-random | segmented rectangular |
| Array physical size (approx.) | 34 m diameter | 30 x 50 m |
| Array alignment | symmetrical | 314 degrees |
| Minimum frequency | 10 MHz | 110 MHz |
| Maximum frequency | 90 MHz | 270 MHz |
| RCU modes | RCU3 & RCU4 | RCU5, RCU6 & RCU7 |
| Beam-forming | digital | analogue in each tile digital over array |
| Elevation limit | 20 degrees | 20 degrees |
| Longitude of array centre (deg East) | 20.7620758 | 20.76103311 |
| Latitude of array centre (deg North) | 69.0707445 | 69.0710561 |
| Altitude of array centre GK (m) | 493.123 | 495.086 |
| Altitude of array centre GRS (m) | 523.371 | 525.336 |
| Geocentric-X coordinate (m) | 2136833.225 | 2136818.264 |
| Geocentric-Y coordinate (m) | 810088.740 | 810038.592 |
| Geocentric-Z coordinate (m) | 5935285.279 | 5935299.531 |
The array altitude is provided with two references 'GK' is to the ETRS-GK27(N60) and 'GRS' is EUREF-FIN Geographic-3D/GRS80
See also:
- KAIRA Array Layout
- KAIRA LBA Polarisation Configuration
- KAIRA HBA Polarisation Configuration
- Converting between subband and frequency
- Mapping RCU number to antenna number
- ASTRON reference on frequencies
- FGI coordinate transform service
Data products
The following is a rough guide to the sorts of data products that are available. Note that additional facilities might be available for specialised experiments. Potential observers are encouraged to discuss their requirements with the KAIRA team to ensure optimal data for their experiment.| Data product | Ext. | Description |
| Subband statistics | SST | all 512 subbands, w/ min. 1-second integration |
| Beamlet statistics | BST | all beamlets, w/ min. 1-second integration |
| Cross correlation statistics | XST | single subband, w/ min. 1-second integration |
| Array covariance cubes | ACC | cross-correlations, stepped subbands, 1s integration only |
| Transient Buffer Board pages | TBB | Transient Buffer Board data |
| Transient Buffer Board raw data | -- | UDP streamed data |
| Beamlet raw data | -- | UDP streamed data |
See also:
- KAIRA Local Pipeline – Lightweight, raw UDP packet recorder
- KAIRA Background Task – Script coordinator for running observations
- KAIRA Data Rates – Data production for different observation types
- KAIRA observing tips – Useful tips and ideas for running a LOFAR station
